Selecting the correct fitting for your particular irrigation project does not seem that difficult until you start searching the internet. Wow! There are so many options and so many different kinds it all of a sudden gets confusing. We hope this will help clear things up so you can choose the right fitting the first time.
Much of it depends on what your project is. A low pressure drip irrigation project uses different piping, so needs different fittings, than a higher-pressure lawn irrigation system. A simple backyard vegetable garden uses a simpler design than a larger commercial crop garden. We will share a bit of information about a variety of fitting categories and uses followed by a list of some of the names of fitting styles to help you search for the correct fitting for your application. Additional information and tips on selecting fittings for drip irrigation can be found in our then Fitting Buying Guide and Fitting Installation Tips.
Low-pressure drip irrigation is becoming more popular as concern for water conservation increases. Most often, drip irrigation operates at less than 30 PSI so LDPE (low density polyethylene) tubing can be used for water distribution from the valve out in most applications. Poly tubing is flexible and easy to work with. Several options for fittings are available for use with poly tubing. Irrigation poly tubing sizes are not standardized so careful planning is necessary to match fitting sizes to tubing inside diameter and outside diameter.
Perma-Loc Fittings are by far the most popular among DIY’ers, as they are durable, easy to use, removable, and reusable. The collar nut is simply turned back towards the center of the fitting exposing the barb; then the tubing is slid over the barb and the collar nut is tightened back out over the tubing holding it securely in place. Perma-Loc Tubing Fittings
Here is a video showing how easy this is.
Perma-Loc Fittings are also available for use with the thin-walled drip tape used in straight row crop applications. These work the same way as the perma-loc tubing fittings but have a slightly different barb and locking collar nut suitable for the thin wall design of drip tape. Perma-Loc Drip Tape Fittings
Barbed Fittings sometimes called insert fittings are very economical and pretty simple to use. Match the inside diameter of the tubing to the barb size as these push into the tubing and are held in place by the sharp barbs in most low pressure systems. Higher pressures may require a clamp placed over the tubing where the barbs are located. Barbed fittings are not easily removable. low-pressureBarbed Tubing Fittings
Compression Fittings are very economical but more difficult to use. You will match the outside diameter of the tubing to the compression fitting size as the tubing is pushed inside this fitting. A sharp edge on the narrowed opening of the compression fitting holds the tubing in place. These fittings are not removable once installed. Compression fittings are very popular with experienced landscapers and installers. We suggest these fittings for those with sufficient agility and hand strength to insert the tubing into the smaller (compressed) opening in the fitting. Compression Fittings
Drip-lock fittings are the newest addition to our drip irrigation fittings. These are a push-fit style from Hydro-Rain/Orbit made for the range of 1/2" drip irrigation poly tubing. These are compatible with tubing outside diameters of .630" - .710 (16 - 18 mm), which are the most common in LDPE drip irrigation tubing. The drip-lock fittings are durable and reliable as well as removable and reusable.
High-pressure systems, such as your pop-up lawn sprinklers, use more durable piping such as PVC, HDPE (high density polyethylene) tubing, and swing pipe. While PVC is used in almost any water distribution system, it is common in higher pressure irrigation. Innovative technology is bringing simpler options to the forefront of lawn irrigation.
Perma-Loc, Barbed, Compression, & Drip-Lock Comparison:
PVC Fittings are available in threaded and slip styles, each having male and female connections in a multitude of shapes and forms. For nearly every problematic situation involving PVC, there is a fitting to help with a solution.
PVC threaded fittings are available as male (threads on the outside) NPT or female (threads on the inside) NPT and will match with iron pipe threads when necessary. Also to make irrigation connections easier many PVC fittings are available with standard ¾” garden hose threads that will connect right to your outdoor water spigot or garden hose. Please note: Pipe threads and hose threads are not compatible with each other so several adapters are available to convert from one to the other.
PVC slip fittings have no threads and will slip over the PVC pipe and are solvent welded (using PVC primer/cement) for a permanent leakproof seal.
Schedule 40 PVC Fittings; Schedule 80 PVC Nipples & Risers
PVC-Lock Fittings use “Push-Fit” technology to achieve a water-tight seal. Inside a PVC-Lock fitting there is a seal and a ring of “teeth” that grab hold of a length of PVC pipe that is simply pushed into the fitting. No solvent or cement is required. This ring allows the fitting to be rotated after joining which can be advantageous in many projects. This means fittings can be removed and reused. Removal tool is required. PVC-Lock fittings are compatible with Schedule 40 PVC pipe. Many of our PVC-Lock fittings have a PVC-Lock connection on one end, and a standard threaded or slip PVC connection on the other. This allows for great flexibility when adapting or joining various PVC fittings and pipes to different sized or threaded connections. different-sized PVC-Lock Fittings
For more detailed information on using PVC-Lock and Blu-Lock check out this link!
Blu-Lock Fittings are the newest addition to the “Push-Fit” technology for use in sprinkler irrigation. The same principle is used in Blu-Lock as in the PVC-Lock, no solvent or cement is needed. This saves time and money plus is safer for you and the environment. However, Blu-Lock is unique in its size and is not compatible with PVC pipe and fittings or poly tubing. Blu-Lock has all its own piping and fittings for downstream of the valve installation only. Blu-Lock fittings are also removable and reusable. Blu-Lock removal tool required.
Blu-Lock Swing Pipe Fittings are for the pipe you run from your Blu-lock lateral up to your riser or sprinkler to get water to the emission device. Blu-lock swing pipe fittings use the same Push-Fit technology as other Blu-Lock products but don’t require a removal tool.
Swing Pipe Fittings are only compatible with high-pressure swing pipe, which generally has an inside diameter of 0.49". These are not compatible with low pressure polyethylene tubing or vinyl tubing and hose. Swing pipe is what is commonly used in lawn/landscape irrigation systems to connect pop-up type sprinklers to the lateral piping. Standard swing pipe fittings and assemblies will be used with standard HDPE swing pipe.
Swing Pipe, Swing Joints, and Swing Assemblies
As we get into bigger commercial irrigation such as crop farms and nursery and greenhouse applications there are even more options, such as Layflat and Oval Hose. We will address those in a separate article.
Common Fitting Forms and Shapes
An adapter is any fitting that adapts one type of connection to another. Such as a PVC slip connection to a threaded connection, changing a pipe thread fitting to a garden hose thread, and even connect poly tubing to a threaded pipe or hose connection.
A bushing is a fitting that fits inside a pipe fitting or another threaded fitting and connects another pipe section or threaded fitting inside of the bushing fitting.
Cap closes the end of a run of pipe, tubing, or hose often fitting over the pipe.
A coupler, often called a coupling or connector, is a straight fitting used to connect two sections of pipe, tubing, or hose together.
Cross is a fitting with four outlets running at 90 degrees of each other.
An elbow is a fitting that creates a turn in the pipe, tubing, or hose.
45 
90 
3-way
The nipple is a straight coupler or riser with male connections or threads at both ends.
Close Nipple
Riser 
Reducing
Plug closes an opening, frequently the end of a threaded fitting.
Another type is a Goof Plug, which can also be used to close a hole that was punched in your poly tubing that is no longer needed.
A reducer is any fitting that connects pipe, tubing, or hose of one size to another smaller (or larger) size pipe, tubing, or hose.
Saddle/Snap Tee can be used to add a new line off of an already installed piping system. The tee fitting snaps over the PVC pipe and then a hole must be drilled into the pipe to open a water passage for the branch pipe. A PVC saddle/snap fitting is solvent welded onto the pipe prior to drilling the hole.
Something like the Blu-Lock Saddle Tap Tee does not require glue or cement, just a snap and a twist of the tap.
A socket is a PVC slip fitting that fits over the pipe of the same nominal size. Slip fittings require solvent welding. Often referred to as the female end.
A spigot is a PVC slip fitting that fits inside a slip socket fitting. Often referred to as the male end. Slip fittings require solvent welding.
Socket/Spigot is a fitting that will function as either. As a socket it fits over the appropriate size PVC pipe and as a spigot, it will fit inside the pvc fitting of the next larger pipe size. Just remember not all PVC slip fittings can function as both a socket and spigot.
Tee fitting has three outlets with one running 90 degrees off the straight connections.
Union is a coupler that can be taken apart for ease of installation and removal of two sections of pipe.
The valve is a coupling fitting with on/off functionality. Most commonly a ball valve with a quarter-turn handle.
Wye has three connection points where at least one connection point veers off the straight line at a slight angle.
